Transmission safe mode

I have a 2003 Range Rover Vogue 4.4. I have been having problems with the auto transmission. About ten mins after driving there is a clunk and the gearbox goes into safe mode and stays in fourth. If I stop the engine for about a minute everything resets and the gearbox is then fine. I had an oil leak in the gearbox and had two stainless pipes which had corroded replaced with aluminium ones. I hoped this would solve the problem. It hasn't. Can anyone help and tell me what is wrong with it and how to repair.

Thanks

give this guy a ring 01283521414,those boxes are prone to oil pump housing wear which stops them been reconned or fixed

"If I stop the engine for about a minute everything resets and the gearbox is then fine."
How long is it fine for after you've reset the controller? Is it just for another 10 minutes?

"I had an oil leak in the gearbox and had two stainless pipes which had corroded replaced with aluminium ones."
The 5HP24 doesn't have any stainless pipes in it so I assume you're referring to the external pipes to & from the transmission oil cooler?

If the TRANS. FAILSAFE PROG message only appears when the transmission fluid is hot and not at all when it's cold then it's more than likely the O-ring seal between the input shaft and the B-clutch drum which has failed. I've fixed around a dozen L322 5HP24s in the last year with exactly this problem.

jamesmartin said:

give this guy a ring 01283521414,those boxes are prone to oil pump housing wear which stops them been reconned or fixed

Click to expand...

On the 5HP24 ?

sorry ,had diesel in mind didnt read properly

It normally happens within the first few minutes of driving. I then stop and turn off for maybe a minute until the code disappears. It is then fine. Saying that I haven't really driven any great distances recently. 25 mins max.

The TRANS. FAILSAFE PROG message can sometimes be caused by a faulty potentiometer reading from the shift motor of your NV225 transfer box. It might be worth eliminating this first before concentrating on the transmission. You simply need to measure the resistance between pins 1 & 2 of the shift motor’s 10-pin plug (photo below). In high range you should get a reading of around 4.7 kilohm.

Hi, I did as Bemble said and the reading was right. I am being told that a few faults came up on the garages diagnostics machine. They think it is not electrical but mechanical even though they are not sure what the codes mean. Quoted £2250 to repair. Are there any other choices first? Big help needed.

Don't know if you got your problem fixed, but I am having the same issues. In April this year I had to have the gearbox fully reconditioned (cost £3200) by TES Transmissions in Westbury, this was after a vehicle servive by TH White of Swindon which cost me £1900 as I only found out then that the car had not been serviced for 2 years! I purchased the car in March 2010.

Anyway, since having the engine sorted and gearbox done, on a return trip from Devon I got a 'Check coolant level' message (which was OK), then about 6 miles from home the car would not come out of 3rd gear, with no error messages! I then found out about the gearbox oil overheat and this 'safe' mode.

I got the gearbox people to check the car and they found no errors in the box, but suggested a radiator change as the VIN number of the car is in a range where there is a known problem where the bottom 6 or 8 rows of the radiator collapse internally, which is where the fluid takeoff for the Gearbox Oil cooler is.

So, radiator changed at a cost of £700 (incl labour and VAT), and on a shortish run to Salisbury, on the way back the sodding thing did it again!

Its since been back to TH White for a diagnostic check, again no errors, so the suggestion from them is to run the car to see if it happens more frequently to try to get an error code.
Next big(ish) thing to replace is the Gearbox Oil cooler which is going to cost around £500 with labour - But I dont want to spend that much if it isn't that!!!

I sold mine. Repaired gearbox £1700. Everything good for a week and then the problems started again. Safe mode faults and the engine was starting to judder, then the steering column collapsed. It was a dog so went. I hope you get yours sorted.

Had exactly the same problem on my 2003 4.4, they found there was a blocked fuel filter and some induction air sensors were faulty causing the engine to be over fuelled and go into safe mode, would cure itself if you turned off the engine and waited a few minutes.
However now getting a rumble from somewhere at certain speeds, sounds like a worn shaft in a bearing vibrating and yesterday it went into safe mode again after months of trouble free driving, turned the engine off for a few minutes and all was well again.

TRansmission Failsafe consistently on a cold start.

I know you have already given the order of how we should solve things, Ive tried resolving the voltage issues, I had a weak battery . Im assuming my voltage issues are taken care of since I checked the voltage on at 2200 rpms and was in the 14 V range and at engine being off was in the 12.2 range.

A local guy here said I should try and replace the transmission oil and filter, but I feel like checking the resistance on the potentiometer is something I should do prior. Have seen pictures of the pin etc to check the resistance on, but where are these located? How do I access them?

mrsamram said:

TRansmission Failsafe consistently on a cold start.

I know you have already given the order of how we should solve things, Ive tried resolving the voltage issues, I had a weak battery . Im assuming my voltage issues are taken care of since I checked the voltage on at 2200 rpms and was in the 14 V range and at engine being off was in the 12.2 range.

A local guy here said I should try and replace the transmission oil and filter, but I feel like checking the resistance on the potentiometer is something I should do prior. Have seen pictures of the pin etc to check the resistance on, but where are these located? How do I access them?

Click to expand...

Oil and filter change is the first job.
12.2 volts equates to an almost flat battery, you need to sort that too.